Deconstruction of Corticospinal Circuits for Goal-Directed Motor Skills

Cell. 2017 Oct 5;171(2):440-455.e14. doi: 10.1016/j.cell.2017.08.014. Epub 2017 Sep 21.


Corticospinal neurons (CSNs) represent the direct cortical outputs to the spinal cord and play important roles in motor control across different species. However, their organizational principle remains unclear. By using a retrograde labeling system, we defined the requirement of CSNs in the execution of a skilled forelimb food-pellet retrieval task in mice. In vivo imaging of CSN activity during performance revealed the sequential activation of topographically ordered functional ensembles with moderate local mixing. Region-specific manipulations indicate that CSNs from caudal or rostral forelimb area control reaching or grasping, respectively, and both are required in the transitional pronation step. These region-specific CSNs terminate in different spinal levels and locations, therefore preferentially connecting with the premotor neurons of muscles engaged in different steps of the task. Together, our findings suggest that spatially defined groups of CSNs encode different movement modules, providing a logic for parallel-ordered corticospinal circuits to orchestrate multistep motor skills.

Keywords: corticospinal neurons; food-pellet retrieval task; goal-directed motor skills; in vivo imaging; motor cortex; muscle control; premotor neurons.

MeSH terms

  • Animals
  • Calcium / analysis
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology
  • Cervical Cord / cytology
  • Cervical Cord / physiology*
  • Forelimb / physiology
  • Joints / physiology
  • Mice
  • Mice, Inbred C57BL
  • Motor Skills*
  • Neural Pathways*


  • Calcium